Geometry: Common Core (15th Edition)

by
Charles, Randall I.

Published by
Prentice Hall

ISBN 10:
0133281159

ISBN 13:
978-0-13328-115-6

Chapter 10 - Area - Get Ready! - Page 611: 10

Answer

positive and negative 15

Work Step by Step

The problem is $b^{2} - 225 =0$ so first we must isolate the variable. To do this, we move 225 to the other side of the equation. Then, we get $b^{2} = 225$ and we put a square root over both $b^{2}$ and $225$ to get b= positive and negative 15.